Putting Dell's Ubuntu Ultrabook to the test

by Thorsten Leemhuis

Tests on Dell's Ultrabook with pre-installed Ubuntu 12.04 show that the manufacturer has gone to some trouble to ensure that it runs well with Linux.

The Dell XPS 13 Developer Edition
Our very first keypress after turning on the Dell XPS 13 Developer Edition (running Ubuntu 12.04) drew no response from the Unity desktop. And with that we thought our test of Dell's Ubuntu Ultrabook for developers was set to go the way of most Linux laptop tests – Linux kind of works, but not really.

But further testing turned up no serious problems, with Ubuntu ultimately running very nicely on the XPS 13. All of the function keys on the laptop, which has been on sale in Europe since the start of March, worked and the keyboard backlighting could be turned on and off. It wasn't possible to scroll window content up and down by gliding a finger along the right hand edge of the touchpad: scrolling required two fingers, in keeping with what is now the default Windows setting. Windows can be moved and resized using three-finger gestures. All this is made possible by a driver that will be included in the 3.9 kernel due for release in late April.

Thanks to a 256GB SSD and a fan which was rarely on, and then generally only at low speed, the Ultrabook is barely audible under normal running conditions. When the load on the dual-core Core i7-3537U processor was increased, the fan audibly rotated for 10 to 20 seconds, producing quite a din. The Ultrabook required about 225 seconds to compile the 3.8 kernel using the default configuration (make defconfig) with no modules (make vmlinux). By comparison, a desktop with a Core i3-3225 takes about 200 seconds and a desktop with a Celeron G550 about 325 seconds to perform the same task.

Dell has neglected to activate a range of energy saving features that can reduce power consumption when idling by 1.5 to 2 watts The Ultrabook, developed under the codename Sputnik 2, has 8GB RAM and an integrated USB webcam. There is no network port and external monitors can only be connected via a Mini DisplayPort. A DisplayPort monitor connected via this port worked correctly, as did a DVI monitor connected via a Mini DisplayPort to DVI adaptor. It is not, however, possible to connect a VGA monitor by adding in a DVI to VGA adaptor.

A minor shortcoming was observed when trying to operate two displays, in that the laptop's full HD display can only operate at a physical resolution of 1920 × 1080 pixels. Since not all projectors support such a high resolution, in many cases it will not be possible to run in clone mode, in which the projector and laptop display the same image and which is preferred by many for giving presentations. Under Fedora 18 and a pre-release version of Ubuntu 13.04, it is possible to set the laptop display to lower resolutions.

The reflective 13.3" display has a brightness of up to 330 nits. From turning on to a ready-to-go desktop interface takes about 15 seconds. The Ultrabook also wakes from standby mode (ACPI S3/suspend-to-RAM) in just under 4 seconds. Hibernation, however, doesn't work. Using the tool dd, we measured a sequential read rate of 482 MB/s and a write rate of 247MB/s on the SSD. From an external SSD connected via USB 3.0, dd was able to read at a rate of only 126MB/s, though the write rate was 241MB/s.

A configuration change needs to be made before the super key will perform its usual function of displaying the dash The non-functioning key with which we started our test was the "super key", which on the XPS 13 Developer Edition, as on most keyboards, sports a Windows logo. Under Unity, this key is supposed to display the Dash. To get this working on the XPS 13, we have to use the Gconf editor to set /apps/compiz-1/plugins/unityshell/screen0/options/show_launcher to the value <Super>.

Dell has been a little sloppy in a few other places too, and has neglected to enable various energy saving features, including for the USB Bluetooth chip and the SATA port to which the SSD is attached. Measuring the input power using a watt meter showed that activating just these two features was sufficient to reduce the 12.5 watt power consumption by more than 1 watt. Activating further energy saving features reduced power consumption by 1.5 to 2 watts, though it should be noted that such measurements are subject to a degree of inaccuracy, in part due to the battery, which is non-removable.

The XPS 13 with Ubuntu is around £120 cheaper than with Windows As delivered, the battery on our test laptop lasted about five and a quarter hours when idling with Bluetooth and wireless active, the display set to a brightness of 200 nits, and the browser displaying a web site set to reload once a minute.

At the time of writing, Dell's UK online shop lists the XPS 13 Developer Edition solely under products for SMEs. Users buying for personal use can also buy from here, but will need to add VAT, increasing the price from the £899 shown to just under £1080. Dell charges around £120 more for an otherwise identical XPS 13 supplied with Windows 8. Both Ultrabooks currently have free delivery.